1. Field of the Invention
This invention relates to a multi-media communication apparatus in which information of a plurality of media including video information (time-varying moving picture information and still picture information), audio information and character information are combined by multiplexing to be transmitted to another multi-media communication apparatus.
2. Description of the Related Art
In a prior art manner of multi-media communication of information including video information, audio information and character information, the user of a conventional multi-media communication apparatus desiring to make communication with another conventional multi-media communication apparatus selected the telephone number of the latter multi-media communication apparatus on a key manipulator part, and, when the user manipulated keys for dialing the telephone number, a call control/processing part of the former multi-media communication apparatus acted to connect the former and latter multi-media communication apparatuses to the communication line through a line interface part. Then, the user of the multi-media communication apparatus inputted the communication rate of audio information on the key manipulator part according to the paragraph H. 221 of the CCITT recommendations thereby determining the channel allocated to the communication line and the frame structure of information including audio information, video information and data information on the basis of the inputted audio signal communication rate. Then, according to the BAS Code (bit-rate allocation signal) defined in the paragraph H. 241 of the CCITT recommendations, the frame structure and multi-media communication capacity were exchanged between the former and latter multi-media communication apparatuses, and the communication mode, etc. between the multi-media communication apparatuses were specified.
As described above, in the case of the prior art multi-media communication apparatuses, the multi-media communication of information including video information, audio information and data information was started after setting of the end-to-end physical connections of initial and additional channels and establishment of the in-channel frame alignment between the apparatuses.
However, when the video information was detected to include incessant scene changes or very fast motion, the density of the video information was made lower by decreasing the number of frames or changing, for example, the parameter of quantization in the quantizing step. Thus, it was the prior art practice that the desired multi-media communication was achieved by multiplexing information including audio information, video information and character information in the manner described above.